3. The genetic code is commaless, which means that no codon is reserved for punctuations. It means that after one amino acid is coded, the second amino acid will be automatically, coded by the next three letters and that no letters are wasted as the punctuation marks (Fig.
Summer solstice is the first day of summer - it's usually between June 20th and June 23rd. In 2016, the summer solstice takes place on June 20th. We know it's summer because the earth's axis tilts toward the sun from June to September - this means warmer weather and longer days.
Around the summer solstice (approximately 21 June in the Northern Hemisphere and 22 December in the Southern Hemisphere) the sun is visible for the full 24 hours, given fair weather. The number of days per year with potential midnight sun increases the farther towards either pole one goes.